1. Field of the Invention
The present invention relates to an earth boring bit for use in forming a wellbore. More specifically, the invention relates to a bit having a packer that is selectively deployable for fracturing a subterranean formation while at the same time drilling a wellbore in the formation.
2. Description of the Related Art
Hydrocarbon producing wellbores extend subsurface and intersect subterranean formations where hydrocarbons are trapped. The wellbores generally are created by drill bits that are on the end of a drill string, where typically a drive system above the opening to the wellbore rotates the drill string and bit. Drill bits are usually equipped with cutting elements that scrape the bottom of the wellbore as the bit is rotated to excavate material from the formation, thereby deepening the wellbore. Drilling fluid is typically pumped down the drill string and directed from the drill bit into the wellbore, where it then flows back up the wellbore in an annulus between the drill string and walls of the wellbore. The drilling fluid cools the bit, maintains a desired pressure in the well, and when flowing up the wellbore carries with it cuttings produced while excavating.
To improve a flow of hydrocarbons from the formation to the wellbore, fractures are sometimes created into the formation from the wall of the wellbore. Fracturing is typically performed by injecting high pressure fluid into the wellbore and sealing off a portion of the wellbore. Fracturing generally initiates when the pressure in the wellbore exceeds the rock strength in the formation. The fractures are usually supported by injection of a proppant, such as sand or resin coated particles; which also employed for blocks the production of sand or other particulate matter from the formation into the wellbore.